1. Epidermis

The epidermis is the plant's outer covering.

• Protects the plant from damage

• Helps reduce water loss

• In roots, it helps absorb water and minerals

• In leaves, it contains stomata for gas exchange

Gas Exchange

Definition:

Gas exchange is the process by which oxygen enters the body and carbon dioxide leaves the body.

Key Points

• Occurs mainly in the alveoli (air sacs) of the lungs.

• Oxygen moves from the air in the lungs into the blood.

PLANT CLASSIFICATION

Plant classification means grouping plants into different categories based on their features. Since there are many kinds of plants in the world, classification helps us study and identify them easily. Plants are grouped according to their size, stem, leaves, roots, flowers, and the way they grow.

Plants are mainly classified into five groups:

Herbs

Herbs are small plants with soft, green stems. They usually live for a short time.

Examples: Mint, coriander, spinach.

What is a Species?

A species is a group of living organisms that are similar to each other and can reproduce with one another.

Their offspring must also be able to grow up and reproduce.

Simple Meaning

If two living things can:

• Mate

SPECIES

Definition

• A species is a group of living organisms that are similar to one another.

• Members of the same species can reproduce and have offspring.

• The offspring can grow up and reproduce too.

• Species are the basic units used to classify living things.

Definition

A species is a group of living organisms that are very similar and can reproduce to produce young ones of the same kind.

Characteristics of a Species

• Members look similar to each other.

• Members have similar features and behaviors.

Definition:

A cell is the smallest living unit of life. All living things are made up of cells.

Parts of a Cell:

1. Cell Membrane.

The cell membrane is the outer covering of the cell. It protects the cell and controls what enters and leaves the cell.

2. Cytoplasm.

Ecosystem:

An ecosystem is a system where living things and non-living things live together and depend on each other.

Living things:

These are things that are alive:

• Plants.

• Animals.

Invertebrates.

Invertebrates are animals without a backbone. They are grouped based on their body shape and structure.

Exoskeleton.

A hard outer covering on the outside of an animal’s body.

1. Porifera.

• Full of tiny holes.

Classification of Vertebrates

Vertebrates are animals that have a backbone. They are grouped into five main groups.

1. Fish

• Live in water.

• Cold-blooded.

• Have scales, fins, and gills.

What is classifying plants?

Grouping plants into different categories.

Why do we classify plants?

There are millions of plants so we need a way to organize them.

What are mosses?

Mosses are very small plants. They produce spores for reproduction.

Investigating Variation:

Means studying the differences between individuals of the same species. It is a way to observe, measure, and understand how living things are not exactly the same.

1. Choose a Feature to Study

Examples

• Height

• Hand span

Variation in Species

Variation in species means that individuals belonging to the same species are not identical. Even though they can reproduce with each other and are part of the same group they show many small and natural differences .These differences can be in height ,skin colour ,body shape, leaf size ,flower colour, speed ,behavior and many other features .All these differences together are known as variation.

What Variation Means?

Variation means that no two individuals of a species look or behave exactly the same . Some differences are easy to see like height or hair type Some differences are hidden like blood group or the way the body works inside.

So same species → many natural differences → variation

Examples of Variation in Humans

A species is a group of living things that share many things in common. They look alike, live in similar ways, and can have babies with each other. The babies they have can also grow up and have babies of their own.

Each species has its own special features. For example, all humans belong to one species because all people can have children together. All dogs belong to another species because all dogs can have puppies together.

Different species cannot have babies together. For example, a cat and a dog are too different. Their bodies, size, and the way their insides work are not the same, so they cannot have babies together.

Every species has its own kind of food, place to live, and way of surviving. Fish live in water and breathe through gills. Birds live on land or in trees and breathe air through lungs. Lions hunt for…

• energy resources are things that give us energy

• everything needs energy

• solar energy comes from the sun

• wind energy comes from moving air

• hydro energy comes from flowing water

• biomass energy comes from plants wood and animal waste

• conservation means taking care of earths natural things

• there are 2 types of conservation renewable resource conservation and non renewable resource conservation

• renewable resource conservation means protecting things that can grow back

• non renewable resource conservation means saving things that cannot come back easily

• conservation is important for life on earth

• we need conservation so things dont run out

• ozone is a gas

• their is a layer of ozone high up in the atmosphere

• the ozone layer is 25 km of the ground

• the sun sends out ultraviolet rays it can harm living organisms

• the ozone layer reduces the ultraviolet ray that reaches the ground

• in 1985 scientists discovered that their is less ozone layer in the antarctic

1. air pollution

air pollution happens when harmful gases dust or smoke mix with the air we breathe

2. water pollution

water pollution happens when dirty or harmful substances mix into water bodies like rivers lakes and oceans

3. land pollution

Land pollution happens when the ground is covered or filled with harmful waste

• long ago people found all their food in the wild

• they hunted and killed animals

• they ate berries and seeds

• they didnt kill all the animals

• they didnt eat all the berries

• they made sure their were some food in the future

• the food we eat gives us energy

• the energy in our food began with the sun

• the sunlight goes in plants giving it energy

• when a deer eats the plant it gets its energy

• when a tiger eats the deer it gets its energy

• energy passes from 1 thing to another

• a place where an organism lives is called a habitat

• each organism has adaptation

• adaptation helps it live in a particular habitat

• fish have gills to breath under water

• giraffes have thin skin to live in the african savanna

• cactus has water in their stems

• protozoa only has 1 cell

• the cell of protozoa has to do everything that the protozoa needs to live

• animals and plants have many cells

• different cells take on different tasks

• every cell is specialized to do a particular function

• red blood cells carry oxygen to the body

• all animals are made of cells

• their are a lot of cells in animals

• like plants animal cells have cell membrane cytoplasm and nucleus

• animal cells dont have cell wall

• nucleus controls the cell

• protozoa are things that only have 1 cell

• all living things are made of cells

• cells cant be seen without microscope

• you need microscope to see cells

• plant cells are often larger then animal cells

• plant cells have a nucleus

• plant cells in sunlight often have chloroplast

• most micro organisms are harmless

• many of them are useful to us

• some micro organisms can make us sick

• diseases caused by micro organisms are called infectious diseases

• one kind of bacterium causes a disease called tuberculosis

• louis pasteur was the first person to discover that micro organisms can cause disease

• muscles are organs that help us move

• the muscles are attached to the bones

• tendons are very strong

• tendons dont stretch

• muscles can get shorter

• when the muscles contract they pull the radius and scapula

• Their are 2 types of joints moveable and fixed joints.

• The jaw bone is joint to the rest of the skull.

• The skull has a fixed joint.

• The shoulder joint can move in almost any direction.

• The cranium is made of several firmly joint together.

• The elbow joint is a hinge joint.

read the textbook

• cell structure means how a cell is made

• all living things are made of cells

• you need a microscope to see cells

• their are 2 main types of cells

• their are 7 main parts of cells

• the smallest cells are in bacteria

• asexual reproduction means making a new living thing only using 1 parent

• the baby looks exactly like the parent

• if a plant grows another plant from it's stem without seeds it's asexual reproduction

• in bacteria it happens in 1 celled things

• in potato , onion or strawberry new plants grow from it's root , stem or leaf

• asexual reproduction is fast and easy

1. Carbohydrates are nutrients found in food.

2. But our body can survive without them.

3. There are 3 types of carbohydrates, monosaccharides, disaccharides, and polysaccharides.

4. Monosaccharides - 1 sugar unit.

5. Disaccharides - 2 sugar units.

6. Polysaccharides - 3 or more sugar units.

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Definition:

Enzymes are proteins that speed up chemical reactions in living organisms.

Function:

They help in digestion and other body processes by making reactions faster.

Examples:

1. Amylase – breaks starch into sugars.

Definition:Enzymes are helpers in our body that make chemical reactions happen faster.

1 Function:They help us digest food so our body can use it.

5 Easy Examples:

1. Amylase – breaks starch in bread, rice into sugar.

2. Protease – breaks protein in meat, egg into smaller parts.

3. Lipase – breaks fat in oil, butter into small pieces.

Definition:

The skeletal system is all the bones in our body. It gives shape, helps us move, and protects organs.

Examples:

1. Skull – protects brain

2. Ribs – protect heart and lungs

3. Spine – helps us stand

What are Nutrients?

Nutrients are useful substances in food that our body needs for energy, growth, repair, protection, and proper functioning.

The 7 Types of Nutrients

1. Carbohydrates – Main energy source, broken into glucose for fuel.

2. Proteins – Build and repair body tissues, make enzymes and hormones.

3. Fats – Store energy, keep the body warm, protect organs, help absorb vitamins.

 Living Things

• They grow and develop.

• Need food, water, and air.

• Can reproduce.

• Respond to changes around them.

Non-Living Things